Word lengths in the first line of the Gettysburg Address

To analyze the word lengths in the first line of the Gettysburg Address with a regular dictionary requires code to catch the KeyError and set a default value:

text = "Four score and seven years ago our fathers brought forth on this
continent, a new nation, conceived in Liberty, and dedicated to the proposition
that all men are created equal"

text = text.replace(',', '').lower()        # remove punctuation

word_lengths = {}                                                               
for word in text.split():                                                       
        word_lengths[len(word)] += 1                                            
    except KeyError:                                                            
        word_lengths[len(word)] = 1                                             

Using defaultdict in this case would be more concise and elegant:

from collections import defaultdict
word_lengths = defaultdict(int)                                                 
for word in text.split():                                                       
    word_lengths[len(word)] += 1                                                


defaultdict(<class 'int'>, {4: 3, 5: 5, 3: 9, 7: 4, 2: 3, 9: 3, 1: 1, 6: 1, 11: 1})

Note that defaultdict is not a built-in: it must be imported from the collections module.

The default_factory function is set to int: if a key is missing, it will be inserted into the dictionary and initialized with a call to int(), which returns 0.